Laundry apparatus

ABSTRACT

Laundry washer and drier equipment is adapted for washing sorted classes of fabrics, such as towelling, bed linens, and &#39;&#39;&#39;&#39;noiron&#39;&#39;&#39;&#39; fabrics. Wash cycle lengths for the various classes of fabric are determined and the washer timer dial is marked for the start and finish time of each fabric. The dial on a drier having dry cycle times equal in length to the wash cycle times has its timer dial marked in the same manner.

finite tates Fairneny atent 1 1 May 22,1973

[54] LAUNDRY APPARATUS [76] Inventor: Samuel Fairneny, 16 Willow Road,

Wellesley, Mass.

[22] Filed: Dec. 27, 1971 [21] Appl. No.: 212,815

Related U.S. Application Data [63] Continuation of Ser. No. 35,394, May7, 1970, abandoned.

[52] US. Cl. ..8/159, 68/12 R, 68/19 Z, 68/20 [51] Int. Cl. D061 33/02[58] Field of Search ..68/12 R, 12 F, 20, 68/19.1,19.2;8/158, 159

[56] References Cited UNITED STATES PATENTS 2,868,004 1/1959 Runde..68/12 R 3,102,407 9/1963 Stilwell ..68/12 R X 3,508,340 4/1970 Kombol....68/12 R X 3,566,063 2/1971 McConnell ..68/12 R X PrimaryExaminer-William 1. Price Attorney-Robert C. Schmertz, Jr.

[57] ABSTRACT Laundry washer and drier equipment is adapted for washingsorted classes of fabrics, such as towelling, bed linens, and no-ironfabrics. Wash cycle lengths for the various classes of fabric aredetermined and the washer timer dial is marked for the start and finishtime of each fabric. The dial on a drier having dry cycle times equal inlength to the wash cycle times has its timer dial marked in the samemanner.

4 Claims, 5 Drawing Figures POWEK IN Patented May 22, 1973 2Sheets-Sheet 2 LAUNDRY APPARATUS This is a continuation of applicationSer. No. 35,394, filed May 7, 1970 and now A method of reducing theoperating time of a hot air laundry drier to match the shorter operatingtime of a washer-extractor. Air directed against the tumbling load ofwet wash in the drier is heated above the boiling temperature of waterand is passed through the load. The humidity of the air leaving the loadis measured, and when it drops to a predetermined low value, heating ofthe air ceases until the air leaving the load drops to a predeterminedtemperature. Cooling of the load then continues at a rate controlled byintermittent heating of the air. At a second predetermined temperature,the application of heat ceases. The length of the drying cycle isprincipally controlled by adjustment of the initial hot air temperature,and may be matched to the operating time of a washer-extractor. In oneembodiment, the air supplied to the load is first elevated to atemperature below that at which the load maybe scorched. Thepredetermined low humidity value is that at which about 90 percent, byweight, of the moisture in the load is removed, the first predeterminedtemperature is about 150 and the second abandoned.

is about 120, and the combined times of first heating and controlledheating are made to equal the operating time of the washer-extractor byadjusting the temperature of the first heating.

A drier adapted to perform in accordance with the above method has ahumidistat set to discontinue the first heat when the predeterminedhumidity value is attained, and thermostatically controlled initiationand termination of a timer controlled, intermittent application of heatduring the cooling down period.

This invention relates to new and improved methods and apparatus forwashing laundry. More specifically, it relates to a new method foroperating a washer and a drier, and to a new method and apparatus foruse in a laundry.

Laundries constructed for the purpose of washing fabrics in largequantities usually employ separate washer-extractor and drying machines.Because of the varying nature of the loads which are normally processed,the operating cycles of these machines are normally of considerablydifferent lengths of time. For example, while a well-designedwasher-extractor may require a maximum operating time of twenty tothirty minutes to thoroughly clean and to extract the excess moisturefrom a wash load, a drier may require as long as an hour to dry the sameload. Such a load would be one, for example, which contains muchtowelling or other highly absorbent fabric.

In the ope ration of a laundry, I have found that many conveniences andsignificant economic advantages can be obtained by operating the drieron a time cycle which corresponds in length, approximately, to the timerequired for operation of the washer-extractor. It then becomespossible, for example, to directly and immediately reload the washerwithout lost washer operating time. When the first load is through thedrier, both machines are ready for reloading at about the same time andthe operator is left free to process the output of the drier while thetwo machines are continuously in use. Thus, where two driers mightpreviously have been used to service one washer, now only one drier isrequired. Also, operator time otherwise lost while waiting for the drierto finish is more usefully employed in subsequent processing of theclean, dried load.

Previously, driers have been operated at low temperatures in order toprotect certain types. or fabrics or garments. I have found that formany applications, particularly for institutions processing their ownlinens, towelling, and uniforms, such as hotels, motels, and hospitals,the fabric content of the loads going through the washers is of apredictable character which lends itself to a high degree ofpre-sorting. This in turn permits more precise control of the mode ofoperation of the laundry machines. For example, since towelling requirestwice the extraction speed permissible in noiron fabrics or required forcottons, a washing machine may be designed to have two basic cycles,each containing the desired extract speeds, and yet having approximatelyidentical total cycle times for either fabl'lC.

Further, since particularly fragile fabrics such as rayons,rubber-containing articles, and the like, are not necessarily mixed inwith other types of fabric, variations can be made in processing'in thedrier which otherwise might result in a hazard of tire. Thus, I havefound that it is safe to raise the initial hot-air temperature in thedrier almost to the scorching point during the initial drying phasewhereas the prior art has restricted itself to the use of lowertemperatures with longer drying times. I have also found that, as aconsequence of using high temperatures for drying, bacteria counts inlaundry loads are reduced to acceptable levels, even though thepreceding wash water temperatures have been reduced. This isparticularly important in the case of no-iron" fabrics which cannotsafely be washed at temperatures above without damage to the resin withwhich they are impregnated, and consequent loss of no-ironcharacteristics. Thus, where no-iron fabrics could not be usedpreviously in institutions because of lack of sterility, it is nowpossible for their labor-saving advantages to be realized by theinstitutions in their bed linen, personal uniforms, and the like.

Most driers of which Iam aware have heretofore employed a constant,thermostatically controlled, heat level throughout the drying cycle,possibly followed by a no-heat cooling down period. I have found thatthe use of a gradually declining temperature is preferable, particularlyin the case of no-iron fabric which may be adversely affected by thermalshock in the drying cycle, as well.

Thus, given a drier whose cycle time for a given fabric is approximatelyequal to that of its associated washer, it is now possible to mark thecontrol equip ment for each machine in an identical way, thus providingsimple, identical operating procedures for each ma-, chine whichsimplify operator training and minimize operator error.

Briefly, these advantages and others which will become apparent fromreading the below appended specification are achieved in the followingmanner.

To obtain matched washer-extractor and drier operating times, themaximum time for efficient operating of the washer-extractor on a highlyabsorbent load is first established. Thus, where fabrics in the washload are classified according to type, cotton and no-iron" fabricsordinarily require less extract time than do towels and the like, evenwhere the extract speed of the washer is raised to its maximum effectivespeed for towelling. For example, in a washer suited for this type oflaundry operation, the extract speed on cottons and no-iron fabrics maybe about 270 rpm, a speed which minimizes wrinkling while permitting aneffective extraction. A speed of 540 rpm. is used for towelling, wherewrinkling is not a serious problem.

The method of drying underlying this concept of matched washing anddrying times is composed of two principal steps or periods: A first orhigh heat period during which the load is exposed to hot air at nearlyscorching temperatures, and a cooling down period during which thetemperature is reduced at a controlled rate to prevent harmful shock tono-iron" fabrics when they are being run. (It will be understood thatwhere no-iron fabrics are not being run, the cooling down rate may beaccelerated by using room air.)

For flexibility of operation, the drying cycle, when embodied in amachine, may be divided into three or more parts: a first, high heatperiod, during which the bulk of the moisture in the load is removed, asecond, cooling down period, during which the load continues to dry at acontrolled rate, and third, hold period, where the load continues to betumbled in the air stream without heat until it is to be removed fromthe machine. The hold period is employed when drying loads of higherfabrics, such as cottons and no-iron fabrics which dry quickly; it keepsthem in motion until the operator is ready to remove them from themachine and so avoids wrinkling which would occur if they were allowedto sit in the machine.

As mentioned above, the cooling down portion of the cycle is importantin handling no-iron fabrics in order to prevent damage. In accordancewith the teachings of the invention, where an initial high heat is usedbut terminated after 90 percent of the moisture is removed, supplementaldrying is also required. As was the case with the washer-extractor,towelling requires the greatest amount of time for drying. This secondpart of the drying cycle, thus, must be fixed first, when settingconditions for matching washer and drier cycles. To this end, the drieris first operated with reasonably elevated initial heats until 90percent of the water, by weight, has been removed from a load oftowelling. The load is then allowed to cool to 150 by tumbling it in theunheated drier air stream, and heat is then supplied intermittently toreduce the cooling rate until the end temperature is reached. Atemperature of 120 is suitable for handling of the load, and iseconomical of heat, as well.

The high heat portion of the cycle may then be determined with towellingloads, while calibrating a humidity sensor to determine the switch-overpoint from the high heat portion to the cooling down portion of thecycle. Towelling loads are dried and weighed at successively highertemperatures until approximately 90 percent of the moisture, by weight,has been removed from the load, and until the length of the high heatperiod, plus the length of the controlled cooling period is equal to thewasher-extractor time. The humidity sensor, which may be activated bythe rising temperature of air leaving the load as it dries byevaporation, can be set so that activation occurs when 90 percentmoisture removal is attained. The length of the cycle is repeatedlyreduced until the total cycle length equals that of the washer-extractorfor the same laundry load. The upper limit of air temperature is thepoint at which scorching of the load begins.

A washer meeting the requirements of the broader aspects of theinvention may, for example, have separate cycles for towelling and forcotton and no-iron fabrics. In the towelling cycle, high extract speedsare used.

A drier embodying the method of the invention may be provided byadapting a conventional hot air tumbler drier. In such a drier a supplyof fresh air is drawn by an exhaust blower down from one or more gasfired burners and directed through a perforated, horizontal, metalcylinder in which the load to be dried is placed. As the cylinder isrotated by an external drive, the heated air is drawn through it andthence passes through a lint trap to the exhaust fan. From the exhaustfan the air is exhausted to the atmosphere through a stack. The burnersshould be capable of heating the input air well above 240. The humiditysensor may be a conventional, temperature activated type, so long as itis sufficiently sensitive to determine accurately the point of percentmoisture removal. It is preferably located in the exhaust stack asufficient distance from the exhaust fan output to minimize variationsinduced by turbulence. The cooling down control thermostats may also belocated in the stack.

Reference is now made to the drawings in which:

FIG. 1 is a schematic view in cross-section taken from the front of adrier embodying the invention;

FIG. 2 is a schematic view in cross-section taken from the side of adrier embodying the invention;

FIG. 3 is a chart showing typical washer-extractor cycles in machinesadapted for operation according to the teachings of the invention;

FIG. 4a. and 4b. illustrate washer and drier control dial platessuitable of use in the practice of the invention.

Referring now to FIG. 1 and 2, a conventional hot air drier is shown inwhich enclosure 2 surrounds and sup ports cylinder or wheel 4 forrotation about its longitu dinal axis on shaft 6. The wash load may beinserted into wheel 6 through front door 8 which is normallyclosedduring the operation of the drier. Electric motor 10, suppliedwith electricity from control box 12, drives cylinder shaft 6 throughdrive pulley l4, drive belt 16, and cylinder shaft pulley 18. In turn,drive belt 20, running in pulley 22 on cylinder shaft 6, turns pulley 24on exhaust fan drive shaft 26. Heat for air pulled through wheel 4 byexhaust fan 28 is supplied by gas burners 30. Gas to burners 30 issupplied by pipe 32 from solenoid valve 34. Solenoid valve 34 iselectrically activated from control box 12. Top baffle plate 36 andsidedeflectors 38 serve, respectively, to prevent the direct incidenceof flame on wheel 4 and to redirect the flow of heated air passingaround baffle 36 to wheel 4, confining the air flow to achieve maximumheating effect on wheel 4 and its contents. Lint screen 40 is placedacross the input of exhaust fan 28 to intercept lint transported by airleaving the load in cylinder 4, preventing passage of lint throughexhaust stack 42 to the atmosphere. The structure of the drier to thispoint, with the possible exception of a larger heating capacity, isconventional, and capable of performing in the usual manner.

Reference is now made to FIGS. 3a, and 3b, which shows cycle sequencesemploying the teachings of the invention as applied to a washer havingseparate towelling, and cotton-no-iron cycles. FIG. 3a, shows the washercycle for towelling as requiring about 19% minutes and using an extractspeed of 540 rpm. It will be noted that the difference between thiscycle and that of the cotton and no-iron cycle of FIG. 3b, is in theextract portion of the cycle. In the latter, extraction occurs at 270r.p.m., and the extract cycles are a half minute shorter. These washcycles are illustrative, having been determined for one type of machineoperating to produce speed to minimize wrinkling of cotton and no-ironfabric consistent with obtaining good extraction of water. Fortowelling, the highest extract speed consistent with mechanicalconvenience in machine design and cycle length, was chosen. It will beunderstood other conventional washer equipment may be modified toperform in accordance with the teaching of the invention by similarmodifications well understood in the art.

FIG. 30 and FIG. 3d show the differences in drier cycles for towellingand no-irons respectively. The basic high heat and controlled cool downportions of the drier curve are denoted by Start to point A, and point Ato Point C, respectively. Between points A and B, no heat is supplied tothe load, and the timer motor is off. Point A is reached when 90 percentof the moisture in the load, by weight, has been removed as determinedby the humidity sensor, and sustained heating of the drier air isstopped. Between points A and B, no heat is supplied to the drier air.Point B is determined by thermostat, when the air leaving the load hasreached 150. At this point, the timer is restarted, and the air to theload is heated intermittently to reduce the rate of cooling and avoidthermal shock, for example, to no-iron fabrics. Since the over all driercycle time has been matched to the washer time for towelling asdescribed above, timer controlled operation of the drier stops, in thecase of a machine having a full, highly absorbent load, when the exhaustair reaches 120 point C on the diagram. In FIG. 3d a hold period from Cto D is shown, during which no heat is supplied to the load. In thiscase the timer shuts the drier down after the predetermined time atpoint D. Cottons and no-irons require much less total drying time thantowelling, and the full, matching drier cycle time is rounded out byoperating the machine to point D with no heat supplied to avoid newwrinkling of the load.

Conventional drier control circuitry is modified according to theteachings of the invention in both drier cycles to provide for start ofthe cycle by rotation of a timer control knob to start timer 44 and toinitiate the high heat, by activating solenoid valve 34. The motor intimer motor 44 need not operate during high heat and during the forcedcool down period. When humidity sensor 46 is activated by the rise intemperature in exhaust stack 8, solenoid valve 46 is closed, as byinterrupting a holding circuit, and cool air is drawn through the loadby continued operation of exhaust blower 28. The humidity sensing devicemay, for example, be a Robertshaw l-Iumidistat Model KXR-2-72, having amaximum temperature setting of 250". With it, 240 exhaust airtemperatures have been found to equal 90 percent moisture removal in atypical 50 pound drier. The load continues to cool while tumbling untilthermostatic control unit 48, located in the stream of air exhaustedfrom the load, senses a temperature of about 150 (point B), the point atwhich the addition of supplemental heat in bursts will not riskscorching the load. A signal from thermostatic control unit 48 returnsthe unit to timer control and solenoid valve 34 is intermittentlyactivated to cool the load at a slower, controlled rate. The coolingrate during this portion of the cooling cycle is, as was stated above,determined by the need to protect no-iron" fabrics from resin damage bytoo rapid cooling and the need to achieve full drying of the load.Intermittent heating is stopped by a second temperature signal fromthermostatic control unit 48, as, for example, from a second thermostatwhich senses exhaust air temperature of (point C) and stops theintermittent heating of the air. When, as in the case of cotton orno-iron loads, cooling to 120 is accomplished prior to the full desireddrier cycle time, tumbling and cooling continues under control of timer34 until full time (point D) has expired.

Advantageous use of the simultaneous operating times provided by thisinvention may be taken by providing controls on the washer and drierwhich duplicate the settings required for the same type of fabric load.FIGS. 4a, and 4b, show a pair of control dial plates; FIG. 4a is for awasher extractor, and FIG. 4b for a drier. The controls to which thesedials are attached may be, for example, of the multiple cam type inwhich a rotary shaft is driven by a timing motor for rotating the shaftonce every hour and a half. The rotary shaft carries a number of camdiscs, each of which has three control profiles spaced around itscircumference to correspond to the three cycles marked on its dialplate, and of which each controls a particular function of theassociated control circuitry. A particularly convenient feature of theinvention is that the orientation of the control pointer knob on eachcontrol is the same for starting each cycle. Thus, the same dialposition or physical setting used on the washer for a load of towels isused on the drier when that load is moved to it. For the sake ofillustration, markings showing the specific part of the wash or drycycle in which the machine is operating at a given time-informationwhich is made available by means of the timer shaft and pointer-isomitted, but one skilled in the art will readily understand that suchmarkings may be supplied.

While I have shown the invention in one embodiment, it will be apparentto those skilled in the art that equivalent components may be used inlaundry systems employing the invention and that specific operatinglimits must be determined for particular machine characteristics. Thus,for example, electric heaters may be substituted for the gas-firedburners, other types of humidity sensor may be used than a humidistat,etc. It is intended, therefore, that the below appended claims be giventhe broadest interpretation in keeping with the spirit of the invention.

I claim:

1. In a laundry, the combination of a washerextractor having at leasttwo predetermined wash cycles of substantially equal operating time, oneof the cycles having a high extract speed for rapid removal of waterfrom highly absorbent fabric loads and another cycle having a lowerextract speed for removal of water from less absorbent fabric loadswhile minimizing wrinkling, and a separate, forced hot air,temperaturecontrolled drier whose operating time, regardless of theabsorbency of its load, is substantially equal to the operating times ofthe washer extractor.

2. The laundry of claim I in which the drier has predetermined cyclescorresponding in number and fabric classification to those of thewasher-extractor, and in which the drier employs an initial hot airtemperature near to, but below, that at which the fabric can bescorched.

3. The laundry of claim 2 in which each machine has identical cycleselector controls with identical physical positions corresponding to theclassification of the loads.

4. The method of operating a laundry having a washer-extractor whichextracts at differing speeds, and a separate forced hot-air drier whichincludes the steps of:

sorting the fabrics to be washed into highly absorbent and moderatelyabsorbent loads while excluding fragile fabrics which might result in ahazard of fire,

establishing a basic cycle time by determining the cycle time for theeffective washing of one or more moderately absorbent loads while usingan effective extract speed which minimizes wrinkling,

matching the basic cycle time in the washer for highly absorbent loadsby obtaining effective extraction at a much higher extract speed, and sodetermining a second washer cycle,

matching the basic cycle time in the drier for washed and extractedhighly absorbent loads by selecting an initial hot air temperature nearto, but below, that at which fabric in the loads is scorched,interrupting heating of the air when the bulk of the moisture is removedfrom the loads, cooling the load to an intermediate temperature, andcontinuing heating of the load until it is dry, adjusting thetemperatures until the basic cycle time is matched, thus establishing afirst drier cycle,

matching the established basic cycle time in the drier for moderatelyabsorbent loads by using an initial hot air temperature near to, butbelow, that at which fabric in the load is scorched, interruptingheating of the air when the bulk of the moisture is removed from theload, cooling the load to an intermediate temperature, heating the air,as needed, until the loads are dry, and continuing operation of themachine without heat, until the cycle time is complete, thus determininga second drier cycle,

and then processing subsequent loads of presorted fabrics by washing afirst load while using the appropriate cycle, transferring the firstload to the drier at the end of the wash cycle and initiating theappropriate dry cycle, reloading the washer without delay and initiatingthe appropriate wash cycle, unloading the drier when its cycle iscomplete, transferring the completed second load from the washer to thedrier without delay and initiating the appropriate dry cycle, reloadingthe washer with a third load and initiating the appropriate cycle, ancontinuing to sequence the presorted loads on the basic cycle time untilall are complete, thereby keeping the machines in continuous use, whileremaining free to perform other tasks during the basic cycle time.

2. The laundry of claim 1 in which the drier has predetermined cyclescorresponding in number and fabric classification to those of thewasher-extractor, and in which the drier employs an initial hot airtemperature near to, but below, that at which the fabric can bescorched.
 3. The laundry of claim 2 in which each machine has identicalcycle selector controls with identical physical positions correspondingto the classification of the loads.
 4. The method of operating a laundryhaving a washer-extractor which extracts at differing speeds, and aseparate forced hot-air drier which includes the steps of: sorting thefabrics to be washed into highly absorbent and moderately absorbentloads while excluding fragile fabrics which might result in a hazard offire, establishing a basic cycle time by determining the cycle time forthe effective washing of one or more moderately absorbent loads whileusing an effective extract speed which minimizes wrinkling, matching thebasic cycle time in the washer for highly absorbent loads by obtainingeffective extraction at a much higher extract speed, and so determininga second washer cycle, matching the basic cycle time in the drier forwashed and extracted highly absorbent loads by selecting an initial hotair temperature near to, but below, that at which fabric in the loads isscorched, interrupting heating of the air when the bulk of the moistureis removed from the loads, cooling the load to an intermediatetemperature, and continuing heating of the load until it is dry,adjusting the temperatures until the basic cycle time is matched, thusestablishing a first drier cycle, matching the established basic cycletime in the drier for moderately absorbent loads by using An initial hotair temperature near to, but below, that at which fabric in the load isscorched, interrupting heating of the air when the bulk of the moistureis removed from the load, cooling the load to an intermediatetemperature, heating the air, as needed, until the loads are dry, andcontinuing operation of the machine without heat, until the cycle timeis complete, thus determining a second drier cycle, and then processingsubsequent loads of presorted fabrics by washing a first load whileusing the appropriate cycle, transferring the first load to the drier atthe end of the wash cycle and initiating the appropriate dry cycle,reloading the washer without delay and initiating the appropriate washcycle, unloading the drier when its cycle is complete, transferring thecompleted second load from the washer to the drier without delay andinitiating the appropriate dry cycle, reloading the washer with a thirdload and initiating the appropriate cycle, an continuing to sequence thepresorted loads on the basic cycle time until all are complete, therebykeeping the machines in continuous use, while remaining free to performother tasks during the basic cycle time.